Device and methodology for the removal of heat from an equipment rack by means of heat exchangers mounted to a door

ABSTRACT

A cooling door assembly includes a frame and a cooling door coupled to the frame. The cooling door includes multiple heat exchangers. The frame is configured to mount to the back of a server rack or other electronics enclosure in such a manner that the cooling door opens to allow access to the electronics servers within the server rack while maintaining a fluidic connection to an external cooling system. The frame is coupled to the external cooling system and the cooling door includes one or more swivel joints, each configured to provide one or more fluid paths between the cooling door and the frame. The cooling door assembly includes separate and independent fluid paths, where fluid is separately provided to each independent fluid path. Different groups of heat exchangers are coupled to each independent fluid path. In the event of failure of one of the independent fluid paths, the other independent fluid path(s) remain operational.

RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 12/291,884, filed Nov. 14, 2008, and entitled “Device andMethodology for the Removal of Heat from an Equipment Rack by Means ofHeat Exchangers Mounted to a Door.” U.S. patent application Ser. No.12/291,884 claims priority of U.S. Provisional Application, Ser. No.61/068,891, filed Mar. 10, 2008, and entitled “Fan Tray for SupplementalAir Flow”, by these same inventors. This application incorporates U.S.patent application Ser. No. 12/291,884 and U.S. Provisional Application,Ser. No. 61/068,891 in their entirety by reference.

FIELD OF THE INVENTION

The invention relates to a method of and apparatus for cooling a heatproducing device in general, and specifically, to a method of andapparatus for cooling server applications using fluid-based coolingsystems.

BACKGROUND OF THE INVENTION

Cooling of high performance integrated circuits with high heatdissipation is presenting significant challenge in the electronicscooling arena. Conventional cooling with heat pipes and fan mounted heatsinks are not adequate for cooling chips with ever increasing wattagerequirements, including those exceeding 100 W.

Electronics servers, such as blade servers and rack servers, are beingused in increasing numbers due to the higher processor performance perunit volume one can achieve. However, the high density of integratedcircuits also leads to high thermal density, which is beyond thecapability of conventional air-cooling methods.

A particular problem with cooling integrated circuits on electronicsservers is that multiple electronics servers are typically mounted inclose quarters within a server chassis. In such configurations,electronics servers are separated by a limited amount of space, therebyreducing the dimensions within which to provide an adequate coolingsolution. Typically, stacking of electronics servers does not providethe mounting of large fans and heat sinks for each electronics server.Often electronics server stacks within a single server chassis arecooled with one or more fans, one or more heat sinks, or a combinationof both. Using this configuration, the integrated circuits on eachelectronics server are cooled using the heat sink and the large fan thatblows air over the heat sink, or simply by blowing air directly over theelectronics servers. However, considering the limited free spacesurrounding the stacked electronics servers within the server chassis,the amount of air available for cooling the integrated circuits islimited.

As data centers continue to increase their computer density, electronicsservers are being deployed more frequently. Fully populated electronicsservers significantly increase rack heat production. This requiressupplemental cooling beyond what the Computer Room Air Conditioning(CRAC) units can provide. Supplemental cooling systems may include fans,pumps, and heat exchangers located outside the back end of theelectronics server to decrease the air temperature exiting theelectronics server. The heat exchangers in these supplemental coolingsystems are supplied with pumped coolants, water, or refrigerants. Whilethese supplemental cooling systems can take advantage of efficiencygained by economies of scale, they still require additional fans. It isdesirable to take advantage of the existing fans in the electronicsserver.

Some supplemental cooling systems are configured as a “cooling door”that is attached to the back of a server rack. Supply and return hosesextend into the data center floor through a large opening. This largeopening is required to provide clearance so that additional hose lengthcan be pulled out of the floor as the door is opened and slid back intothe floor when the door is closed. The space in the floor is usuallyunder a positive pressure with air being supplied from CRAC units. Thefloor opening can cause a loss in efficiency as some amount of chilledair escapes from under the floor through this opening. Further, pullingadditional hose out of and sliding the hose back into the opening is atedious, and sometimes difficult, activity for the user opening andclosing the cooling door. Still further, since the hose is connected tothe cooling door as the door is opened and closed, physical strain isplaced on the cooling door and hose connection, which creates wear andtear on, and possibly damage to, the connection components.

SUMMARY OF THE INVENTION

Cooling systems of the present invention are directed to a cooling doorassembly including one or more heat exchangers. In some embodiments, thecooling door assembly includes a frame and a cooling door coupled to theframe. The frame is configured to mount to a server rack, cabinet, orother electronics enclosure in such a manner that the cooling door opensto allow access to the electronics servers within the server rack whilemaintaining a fluidic connection to an external cooling system. Thecooling door and frame are mounted together to form a stand-alonecooling door assembly with input and output plumbing to the externalcooling system. There is no plumbing within the server rack andtherefore the cooling door assembly does not include plumbing into andout of the server cabinet. As such, there is no need to modify anexisting server cabinet for plumbing when adding the cooling doorassembly to the server cabinet. The cooling door assembly is configuredas a retrofit assembly to the server cabinet. The frame of the coolingdoor assembly can be designed to mate to different sized servercabinets. The frame is coupled to the external cooling system, and thecooling door includes one or more swivel joints configured to provideone or more fluid paths between the cooling door and the frame. In thismanner, the frame remains in a fixed position, while the cooling door isconfigured to rotate relative to the frame so as to open and close,while maintaining the one or more fluid paths through each swivel joint.

The cooling door assembly does not include hoses that are pulled in andout of the floor when the cooling door is opened and closed. The coolingdoor assembly can be hard plumbed or virtually hard plumbed since theuse of highly flexible hoses is no longer used as a connection to anexternal cooling system. In addition, since highly flexible hoses are nolonger used, metal tubes and pipes can be used, which allows for the useof refrigerants, such as R-134. With the use of refrigerant, an increasein cooling capacity can be obtained.

In some embodiments, the frame includes mounting blocks that are coupledwith external fluid interconnects for supplying and returning fluid froman external source, such as an external cooling system. The externalcooling system can include a cooling tower, a chiller, or othersecondary cooling loop including a heat exchanger used to cool the fluidexiting the cooling door assembly. The types of fluid that can be usedinclude, but are not limited to, water, refrigerant, or any othercoolant. In some embodiments, the fluid is a two-phase fluid. In otherembodiments, the fluid is a single-phase fluid. Fluid flow rate controlscan be included to optimize the fluid flow rate within the cooling doorassembly. In some embodiments, the fluid flow rate controls areimplemented using flow rate valves under the control of a controlmodule.

The mounting blocks, including a supply mounting block and a returnmounting black, are each configured using one of a number of variousconnection types, and with one or more input/output openings. Forexample, the supply mounting block can have 1, 2, or more inputconnections depending on the amount of fluid that is required. Eachinput connection is coupled to a separate external supply line. The samecan be done on the return mounting block, where each output connectionis coupled to a separate external return line. The connection types canbe a flare fitting, a threaded connection, or other common types ofconnection. In a two-phase system, there is an extra pressure drop thatoccurs when a fluid is in the gas phase. In this case, the cooling doorassembly can be configured to have a supply mounting block with a singleinput coupled to a single fluid supply line, and a return mounting blockwith multiple outputs coupled to multiple return lines, for example. Ifthe connection type has too high a fluid pressure drop, then themounting blocks can be configured with multiple supply or returnconnections. The frame including the mounting blocks is designed suchthat the mounting blocks are interchangeable so that differentconnection types and number of connections are readily available bysimply switching mounting blocks.

In some embodiments, both the supply mounting block and the returnmounting block are located at the top of the frame. In otherembodiments, the mounting blocks are located at the bottom of the frame,such as when a chilled water loop is used. It is also possible toposition the mounting blocks in a configuration such that one is at thetop and one is at the bottom. In some configurations, one or moremounting blocks are located at the top of the frame and one or moremounting blocks are located at the bottom of the frame. This may be thecase if the system is coupled to one or more different cooling loops inorder to provide redundancy in case of failure. The mounting blocks aredesigned to add minimal pressure drop to the system.

The mounting blocks are fixed in position relative to the frame. Thecooling door is rotatably coupled to the frame through the use of fluidswivel joints, also referred to as rotary unions. The swivel jointallows fluid to pass through a hinge that allows rotation to occur andalso provides a fluid path between the fixed mounting block and therotating cooling door. A swivel joint is coupled to at least one of themounting blocks. In some embodiments, the swivel joint is configuredwith a single fluid path. In other embodiments, the swivel joint isconfigured with multiple fluid paths. Multiple load-bearing mechanicalhinges can be used to attach the cooling door to the frame.

A heat exchanger system on the cooling door is configured to transferheat from the air passing over the heat exchanger surfaces into thefluid flowing within the heat exchangers. The heat exchangers aredesigned with a low airflow impedance. This allows the existing airmovers in the electronics enclosure to be used to provide the air flowfor cooling. Optionally, a separate fan tray is attached to the coolingdoor to provide better air flow.

In some embodiments, the heat exchangers are made of a micro-tubeconstruction with attached air fins or of a tube-fin type of design. Thecooling door can include a single large heat exchanging panel or groupsof heat exchanging panels attached in parallel or series. Separate heatexchanging panels are more manageable to construct and provide bettercontrol of fluid distribution. In some embodiments, each heat exchangingpanel has its own separate flow regulator or valve for regulating theamount of fluid flow within the panel. The regulators or valves can beset so that each panel gets equal fluid flow or each panel gets adifferent amount of fluid. In other embodiments, a flow controlregulator is positioned at any point on the fluid supply side of theheat exchanging panels, such as in a frame supply line or a cooling doorsupply line.

The system of heat exchanging panels can be oriented so that fluid flowis either in the horizontal orientation or the vertical orientation.Separate panels also enable one or more windows to be included in thecooling door. Heat exchangers are difficult to see through. By breakingup the cooling door into a series of panels, one or more windows can beadded in between the heat exchangers so that one can see into theenclosure. This is particularly useful to see warning lights. Eachwindow is covered with a transparent material so as to prevent airflowthrough the window opening.

In some embodiments, the multiple heat exchanging panels are coupled toeach other either in series, in parallel, or a series-parallelcombination via mounting piping to make a rigid assembly. In someembodiments, the heat exchangers are organized into groups of one ormore heat exchangers. Each group is supplied with an independent sourceof fluid so as to provide separate and independent fluid paths throughthe cooling door assembly.

In order for the cooling door to properly open and close withoutbinding, the mechanical hinges and the swivel joints optimally have alltheir axis of rotation co-linear. If the axis are not collinear, thensome amount of flex is required to prevent binding. To accomplish this,flexible tubing is used in key areas on the cooling door. This allowsfor some flex and misalignment to be taken up. Flexible tubing orflexible piping generally has better bending flex than it has theability to torsionally flex (twist) or axially flex (longer or shorter.)To overcome this, sections of flexible piping are assembled togetherwith a non-flexible right-angle bend. The non-flexible right-angle bendallows one arm to move axially because the movement is taken up be abend in flexible tubing coupled to the other arm. Both flexible membersallow flex in three-dimensions. An alternative way of accomplishing thisis by using a four-bar linkage. The four bar linkage allows for movementof the swivel joint without changing the rotational orientation of theswivel joint.

In some embodiments, the cooling door assembly is configured with abranching fluid flow path, where fluid is supplied to the branchingfluid flow path by consolidating the fluid input at one or more externalsupply line interconnects into a common fluid supply for the coolingdoor. In this manner, the fluid source provided to this configuration ofthe cooling door assembly is conceptually considered as a “singlesource”, although multiple different external supply lines are coupledto the external supply line interconnects. In other embodiments, thecooling door assembly is configured with separate and independent fluidpaths, where fluid is separately provided to each independent fluidpath. In this manner, the fluid source provided to this configuration ofthe cooling door assembly is conceptually considered as a “multiplesource”, where the multiple different external supply lines coupled tothe external supply line interconnects are not consolidated into asingle source of fluid, but instead are separately directed to each ofthe independent fluid paths. Different groups of heat exchangers arecoupled to each independent fluid path. In the event of failure of oneof the independent fluid paths, the other independent fluid path(s)remain operational.

Other features and advantages of the present invention will becomeapparent after reviewing the detailed description of the embodiments setforth below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a cooling door assembly coupled to an electronicsenclosure according to an embodiment of the present invention.

FIG. 2 illustrates an enlarged portion of the cooling door assembly ofFIG. 1.

FIG. 3 illustrates a cooling door assembly coupled to the electronicsenclosure according to another embodiment of the present invention.

FIG. 4 illustrates a cooling door assembly coupled to the electronicsenclosure according to yet another embodiment of the present invention.

FIG. 5 illustrates a cooling door assembly configured according to yetanother embodiment of the present invention.

FIG. 6 illustrates an enlarged top portion of the cooling door assemblyof FIG. 5 with a portion of the frame paneling removed.

FIG. 7 illustrates an enlarged bottom portion of the cooling doorassembly of FIG. 5 with a portion of the frame paneling removed.

FIG. 8 illustrates a cooling door assembly including multipleindependent fluid paths according to an embodiment of the presentinvention.

FIG. 9 illustrates a cooling door assembly including multipleindependent fluid paths according to another embodiment of the presentinvention.

FIG. 10 illustrates a cooling door assembly including multipleindependent fluid paths according to yet another embodiment of thepresent invention.

The present invention is described relative to the several views of thedrawings. Where appropriate and only where identical elements aredisclosed and shown in more than one drawing, the same reference numeralwill be used to represent such identical elements.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

Reference will now be made in detail to the embodiments of the coolingsystem of the invention, examples of which are illustrated in theaccompanying drawings. While the invention will be described inconjunction with the embodiments below, it will be understood that theyare not intended to limit the invention to these embodiments andexamples. On the contrary, the invention is intended to coveralternatives, modifications and equivalents, which may be includedwithin the spirit and scope of the invention as defined by the appendedclaims. Furthermore, in the following detailed description of thepresent invention, numerous specific details are set forth in order tomore fully illustrate the present invention. However, it will beapparent to one of ordinary skill in the prior art that the presentinvention may be practiced without these specific details. In otherinstances, well-known methods and procedures, components and processeshaven not been described in detail so as not to unnecessarily obscureaspects of the present invention.

Embodiments of the present invention are directed to a cooling systemthat transfers heat generated by one or more electronics servers withina server rack. The cooling system described herein can be applied to anyelectronics sub-system that is mounted to a backplane, including but notlimited to, a blade server and a rack server, herein referred tocollectively as an electronics server. A server chassis is configured tohouse multiple electronics servers. Each electronics server is coupledto a backplane or mid-plane within the server chassis. Each electronicsserver includes one or more heat generating devices as is well known inthe art.

FIG. 1 illustrates a cooling door assembly 10 coupled to an electronicsenclosure 80 according to an embodiment of the present invention. Thecooling door assembly 10 includes a frame 12 and cooling door 14. Theframe 12 is coupled to the electronics enclosure 80 using anyconventional attachment means including, but not limited to screws,bolts, and rivets. In some embodiments, the frame 12 is additionallyfitted with one or more flanges (not shown) on the top, sides and/orbottom. The one or more flanges provide mechanical support whilemounting the frame 12 to the electronics enclosure. The cooling doorassembly 10 “hangs” on the back of the electronics enclosure 80 usingthe one or more flanges while the frame 12 is being mounted. In someembodiments, an adapter mounting mechanism is mounted to the electronicsenclosure. The adapter mounting mechanism provides a mounting surface towhich the frame 12 is mounted. The frame 12 is coupled to the one ormore flanges or the mounting surface using one or more attachment meansincluding, but not limited to, bolts, screws, and rivets. The flangesare either fixed in position or are designed to be adjustable at thetime of installation. In some embodiments, the cooling door assembly 10is pre-assembled, ready to be attached in the field, thus the coolingdoor assembly 10 can be designed to be universal. The cooling doorassembly 10 can be made in the style of a pre-hung door with the frame12 and the cooling door 14 already fitted and plumbed inside. In someembodiments, the frame 12 is mounted to the electronics enclosure 80 andcan be custom designed for each cabinet, while the actual cooling door14 within the frame 12 is a standard size. In other embodiments, thecooling door assembly 10 is integrated into the electronics enclosure 80during construction.

One or more external supply lines 20 provide fluid from an externalsource, such as an external cooling system, to the cooling door assembly10 via a supply mounting block 16 within the frame 12. As shown in FIG.1, two external supply lines 20 are coupled to the supply mounting block16. It is understood that the supply mounting block can be configured tocouple with more or less than two external supply lines. The use ofmultiple supply lines provides system scalability. Frame supply lines 24and 26 couple the supply mounting block 16 to a swivel joint 28 on thecooling door 14. The frame supply lines 24 and 26 are included withinthe frame 12.

A flex assembly 38 is coupled to the swivel joint 28, and a cooling doorsupply line 40 is coupled to the flex assembly 38. A heat exchangingpanel 8 is coupled to the cooling door supply line 40 via a panel supplyline 42. The heat exchanging panel 8 is also coupled to a cooling doorreturn line 58 via a panel return line 50. A heat exchanging panel 6 iscoupled to the cooling door supply line 40 via a panel supply line 44.The heat exchanging panel 6 is also coupled to the cooling door returnline 58 via a panel return line 52. A heat exchanging panel 4 is coupledto the cooling door supply line 40 via a panel supply line 46. The heatexchanging panel 4 is also coupled to the cooling door return line 58via a panel return line 54. A heat exchanging panel 2 is coupled to thecooling door supply line 40 via a panel supply line 48. The heatexchanging panel 2 is also coupled to the cooling door return line 58via a panel return line 56. Each heat exchanging panel includes a fluidinput header and a fluid output header. The fluid input header isconfigured with one or more fluid input ports, and the fluid outputheader is configured with one or more fluid output ports. The panelsupply line for each heat exchanging panel is coupled to thecorresponding fluid input header, and the panel return line for eachheat exchanging panel is coupled to the corresponding fluid outputheader. Where the fluid input header includes multiple fluid inputports, either a single common panel supply line is coupled to themultiple fluid input ports, or a separate panel supply line is coupledfrom the cooling door supply line to each of the fluid input ports.Where the fluid output header includes multiple fluid output ports,either a single common panel return line is coupled to the multiplefluid output ports, or a separate panel return line is coupled from eachof the fluid output ports to the cooling door return line. In someembodiments, the cooling door 14 is configured such that fluid flowthrough each of the heat exchanging panels 2, 4, 6, 8 is from bottom totop. Such a configuration provides a more consistent and uniform fluidflow through the heat exchanging panels than a top to bottom fluid flowconfiguration.

The cooling door return line 58 is coupled to a flex assembly 36, andthe flex assembly 36 is coupled to a swivel joint 30. The swivel joint30 is coupled to one or more external return lines 22 via a returnmounting block 18. As shown in FIG. 1, two external return lines 22 arecoupled to the return mounting block 18. It is understood that thereturn mounting block can be configured to couple with more or less thantwo external return lines.

The cooling door assembly 10 shown in FIG. 1 includes two mountingblocks, the supply mounting block 16 and the return mounting block 18,each positioned at the top of the frame 12 to match the position of theexternal supply and return lines. In alternative embodiments, either orboth of the mounting blocks can be positioned on the bottom of the frame12. In this alternative configuration, the mounting blocks can bepositioned to match a position of the external supply and return lines,or the external supply and/or return lines can be rerouted to match adesired position of the mounting blocks. Still alternatively, more thantwo mounting blocks can be positioned in the top, bottom, or combinationof top and bottom of the frame 12. Each mounting block is configuredwith one or more fluid paths passing therethrough.

The cooling door 14 is coupled to the frame 12 using a plurality ofmechanical hinges 32, 34. The mechanical hinges 32, 34 are configured asload-bearing connection points and are also configured to enable thecooling door 14 to rotate relative to the frame 12. Although twomechanical hinges 32 and 34 are shown in FIG. 1, it is understood thatthe cooling door assembly can be configured to include more than twomechanical hinges. In some embodiments, the swivel joints are configuredas load-bearing connection points, where the functionality of the swiveljoint, such as swivel joint 28, and the mechanical hinge, such asmechanical hinge 32, are integrated within a single element.

Each swivel joint 28, 30 is configured to enable the cooling door 16 torotate relative to the frame 12, and in particular relative to themounting block 18 and the frame supply line 26, while maintaining asealed fluid path between the frame 12 and the cooling door 14.

In operation, fluid is provided to the supply mounting block 16 via theexternal supply lines 20. The fluid flows through the supply mountingblock 16, through the frame supply lines 24 and 26 and to the coolingdoor 14 via the swivel joint 28. Fluid flows from the swivel joint 28through the flex assembly 38 to the cooling door supply line 40. Fluidis provided to each of the heat exchanging panels 2, 4, 6, 8 from thecooling door supply line 40 via the panel supply lines 48, 46, 44, 42,respectively. Fluid flows through each of the heat exchanging panels 2,4, 6, 8 to the panel returns lines 56, 54, 52, 50, respectively, andinto the cooling door return line 58. Fluid flows from the cooling doorreturn line 58 through the flex assembly 36 to the swivel joint 30 andinto the return mounting block 18. Fluid is output from the cooling doorassembly 10 to the external return lines 22 via the return mountingblock 18. Air from inside the electronics enclosure 80 is directed outof the enclosure through each of the heat exchanging panels 2, 4, 6, 8within the cooling door 14. As air passes through each of the heatexchanging panels 2, 4, 6, 8, and over the heat exchanging surfaces ofthe heat exchanging panels 2, 4, 6, 8, heat is transferred from the airto the fluid flowing through the heat exchanging panels 2, 4, 6, 8. Theheated fluid is then output from the cooling door assembly 10 to anexternal cooling system via the external return lines 22, where thefluid is cooled and returned to the cooling door assembly 10 via theexternal supply lines 20.

FIG. 2 illustrates an enlarged portion of the cooling door assembly 10of FIG. 1. The flex assembly 36 includes a rigid right-angle bend 64, aflexible piping 68 coupled to a first end of the rigid right-angle bend64, and a flexible piping 66 coupled a second end of the rigidright-angle bend 64. The flexible piping 66 is coupled to the coolingdoor return line 58. The flexible piping 68 is coupled to the swiveljoint 30. Use of the flexible piping 66 and 68 allows for forgiveness incomponent and alignment tolerances and movement in three-dimensions. Themechanical hinges 32 and 34 (FIG. 1) and the swivel joints 30 and 28(FIG. 1) optimally have all their axis of rotation co-linear in orderfor the cooling door 14 to properly open and close without bindingwithin the fluid flow path. If the axis are not collinear, then someamount of flex is required to prevent binding. The flexible piping 66and 68 allows for some flex and misalignment to be taken up. The rigidright-angle bend 64 allows one arm, such as the flexible piping 68 tomove axially because the movement is taken up by a bend in the otherarm, such as the flexible piping 66. Such a flexible configurationallows for flexibility in the alignment of components in the joints,heat exchanger panels, and non-moving parts of the cooling door duringnormal use. The flexible configuration also assists in the alignment ofcomponents during assembly.

The return mounting block 18 shown in FIG. 2 includes threeinterconnection openings for coupling with the external return lines 22and the swivel joint 30. Specifically, an interconnection opening 70 isconfigured to couple with an interconnect 80 of a first external returnline 22, and an interconnection opening 72 is configured to couple withan interconnect 82 of a second external return line 22. The returnmounting block 18 also includes a third interconnection opening (notshown) configured to couple with a first interconnect (not shown) of theswivel joint 30. Similarly, the supply mounting block 16 shown in FIG. 2includes three interconnection openings for coupling with the externalsupply lines 20 and the frame supply line 24. Specifically, aninterconnection opening 74 is configured to couple with an interconnect60 of a first external supply line 20, and an interconnection opening 76is configured to couple with an interconnect 62 of a second externalsupply line 20. The supply mounting block 16 also includes a thirdinterconnection opening (not shown) configured to couple with a firstinterconnect (not shown) of the frame supply line 24.

In some embodiments, each of the panel supply lines 42, 44, 46, and 48include a flow control regulator or valve. As shown in FIG. 2, the panelsupply line 48 includes a flow control regulator or valve 78. The flowcontrol regulators or valves are configured to balance fluid flow ineach of the heat exchanging panels 2, 4, 6, 8. Alternatively, the flowcontrol regulators or valves are used to independently regulate fluidflow within each of the heat exchanging panels 2, 4, 6, 8. The flowcontrol regulators or valves can also be used shut off fluid flow to theheat exchanging panels, either for servicing or capacity reasons. Insome embodiments, a heat removal capacity of the cooling door assembly10 can be changed by replacing flow control regulators with a first flowrate with flow control regulators with a different flow rate. In otherembodiments, a flow control regulator is positioned in the frame supplyline or the cooling door supply line. In general, a flow controlregulator can be positioned in any part of the supply side fluid lines.

As shown in FIG. 1, the cooling door assembly is configured as a passivesystem that relies on air movement generated within the electronicsenclosure 80, for example fans included within the electronics enclosureto cool electronics servers. In this configuration, there are noadditional fans used to move the air through the one or more heatexchanger panels in the cooling door. In other embodiments, the coolingdoor assembly is configured as an active system configured to regulateand/or adjust the air flow directed at and through the cooling door. Theactive system includes one or more of a fan tray, airflow guides, one ormore air movers, one or more thermal sensors, one or more anemometers,and a control module. The air flow guides are configured to guidecooling air in a defined manner. The one or more air movers, such asfans, are either fixed or variable speed. The one or more thermalsensors and the one or more anemometers are positioned in the airstreamprior to the one or more heat exchangers and/or in the airstream afterthe one or more heat exchangers. The one or more anemometers measure therate of airflow and the one or more thermal sensors measure thetemperature. The control module is configured to use data received fromthe one or more thermal sensors and/or the one or more anemometers toadjust the fan speeds into favorable performance zones, therebyincreasing efficiency of the system. The system can also be configuredsuch that the control module controls the fluid flow rate by controllingthe flow control regulators or valves.

The cooling door assembly shown in FIGS. 1 and 2 is an exemplaryconfiguration. It is understood that the various components can bepositioned and sequenced in different configurations to achieve the sameor similar results. For example, the frame can be configured withexternal supply line and external return line interconnects that areseparate from the mounting blocks. In such a configuration, theinterconnect openings of the mounting blocks are not directly connectedto the external supply and return lines. Instead, intermediate framereturn and supply lines within the frame are coupled between themounting blocks and the external supply and return lines. Anotheralternative configuration includes coupling a mounting block to eachswivel joint, providing additional support and alignment of the coolingdoor relative to the frame.

FIG. 3 illustrates a cooling door assembly 110 according to anotherembodiment of the present invention. The cooling door assembly 110 isconfigured to be mounted to an electronics enclosure, such as theelectronics enclosure 80 (FIG. 1). The cooling door assembly 110 isconfigured and operates similarly to the cooling door assembly 10(FIG. 1) except that the mounting blocks 116 and 118 of the cooling doorassembly 110 are not coupled directly to the external supply lines (notshown) and the external return lines (not shown). Specifically, thecooling door assembly 110 includes frame supply interconnects 180 and182 configured to be coupled to the external supply lines. The framesupply interconnects 180 and 182 are coupled to the frame supply line124 via a frame supply line 190. The cooling door assembly 110 alsoincludes frame return interconnects 184 and 186 configured to be coupledto the external return lines. The frame return interconnects 184 and 186are coupled to the mounting block 118 via a frame return line 188.Although a single frame return line 188 is shown in FIG. 3, more thanone frame return line can be coupled between the frame returninterconnects and the mounting block. Additionally, the mounting block116 is not positioned in the top of the frame 112, as in the coolingdoor assembly 10 (FIG. 1), but instead the mounting block 116 ispositioned at the bottom of the frame 112 and is coupled to the swiveljoint 128.

The cooling door assembly 110 is also configured to operate within atwo-phase cooling system. In such a system, fluid input to the coolingdoor assembly 110 is in a liquid phase, and the fluid output from thecooling door assembly 110 is in a gas phase or a combination of liquidand gas phase. The fluid in the cooling door assembly 110 remains in theliquid phase until it enters the heat exchanging panels 102, 104, 106,108. In an exemplary application, the mass flow rate of the fluidthrough the cooling door assembly is substantially constant. Since fluidin a gas phase has a greater volume than the same fluid in a liquidphase, the return lines in the cooling door assembly 110 are configuredwith a greater diameter than the supply lines within the cooling doorassembly 110. Accordingly, the frame supply interconnects 180 and 182have a smaller diameter than the frame return interconnects 184 and 186.The frame supply lines 124, 126, and 190, the cooling door supply line140, and the panel supply lines 142, 144, 146, and 148 have a smallerdiameter than the frame return line 188, the cooling door return line158, and the panel return lines 150, 152, 154, and 156. The componentsof the flex assembly 138 have smaller diameters than the components ofthe flex assembly 136. The interconnects of the swivel joint 128 and themounting block 116 are smaller in diameter than the interconnects of theswivel joint 130 and the mounting block 118, respectively. Similarly,the external supply line interconnects (not shown) and the externalsupply lines (not shown) have a smaller diameter than the externalreturn line interconnects (not shown) and the external return lines (notshown), respectively. Configuring the components in the supply path withsmaller diameters than the complimentary components in the return pathfunctions to alleviate increased pressure due to the phase change of thefluid from liquid to gas. In other embodiments, the cooling doorassembly 110 is configured for single-phase cooling.

In some embodiments, a single swivel joint and a single mounting blockare used, where the swivel joint and the mounting block coupled to theswivel joint are each configured with at least two independent fluidpaths. One fluid path is used to supply fluid to the cooling door fromthe frame, and another fluid path is used to return fluid from thecooling door to the frame. In such a configuration, a flex assembly anda cooling door supply line are used to couple the single swivel joint toeach of the panel supply lines.

FIG. 4 illustrates a cooling door assembly 210 configured according toanother embodiment of the present invention. The cooling door assembly210 is configured to be mounted to an electronics enclosure, such as theelectronics enclosure 80 (FIG. 1). The cooling door assembly 210functions similarly as the cooling door assemblies 10, 110 except thecooling door assembly 210 includes a single swivel joint 230 and asingle mounting block 218, as opposed to the two swivel joints and thetwo mounting block of the cooling door assemblies 10, 110. The swiveljoint 230 is configured with two independent fluid paths, a supply fluidpath to supply fluid from the frame 212 to the cooling door 214, and areturn fluid path to return fluid from the cooling door 214 to the frame212. In some embodiments, the two-path swivel joint 230 is a co-axialswivel joint having a center fluid path and an outer fluid path, similarconceptually to a pipe within a pipe where each pipe is capable ofrotating about a center axis. The supply fluid path of the swivel joint230 is coupled to a cooling door supply line 240 via a flex assembly238. The cooling door supply line 240 is coupled to panel supply lines242, 244, 246, 248, which are in turn coupled to heat exchanging panels208, 206, 204, 202, respectively, to receive input fluid.

The heat exchanging panels 208, 206, 204, 202 are also coupled to panelreturn lines 250, 252, 254, 246, respectively, to output fluid from theheat exchanging panels. The panel return lines 250, 252, 254, 256 arecoupled to a cooling door return line 258, which is coupled to a flexassembly 236. The flex assembly 236 is coupled to the return fluid pathof the swivel joint 230.

The mounting block 218 also includes two independent fluid paths, asupply fluid path and a return fluid path. The supply fluid path of themounting block 218 is coupled to the supply fluid path of the swiveljoint 230 and to one or more frame supply lines (not shown). The framesupply line(s) is coupled to frame supply interconnects 280, 282. Thereturn fluid path of the mounting block 218 is coupled to the returnfluid path of the swivel joint 230 and to one or more frame return lines(not shown). The frame return line(s) is coupled to frame returninterconnects 284, 286. As shown in FIG. 4, the cooling door assembly210 is configured for two-phase cooling since the frame supplyinterconnects 280, 282 are smaller in diameter than the frame returninterconnects 284, 286. Accordingly, each of the supply-side fluid linesare smaller in diameter than the return-side fluid lines, as previouslydescribed. In other embodiments, the cooling door assembly 210 isconfigured for single-phase cooling.

The cooling door 214 is mounted to the frame 212 using a plurality ofhinges, such as hinges 232 and 234. In some embodiments, the swiveljoint 230 is also configured as a load-bearing hinge.

The single swivel joint configuration of the cooling door assembly 210reduces the number of swivel joints and mounting blocks, and alsoreduces the amount of frame fluid lines used to direct fluid flow to andfrom the cooling door 214. The cooling door assembly 210 can beconfigured as either a single-phase cooling system or a two-phasecooling system.

The cooling door assemblies described and illustrated in relation toFIGS. 1-3 include two swivel joints. In some embodiments, more than twoswivel joints can be used. In this configuration, the frame includesreconfigured and/or additional fluid supply lines and fluid return linesto accommodate the additional swivel joints. In an exemplaryconfiguration, a pair of swivel joints are coupled to each heatexchanging panel, one swivel joint to supply fluid, and one swivel jointto return fluid to the fluid lines coupled to the frame. In anotherexemplary configuration, a pair of swivel joints is coupled to multipleheat exchanging panels coupled in series, such as a fluid supply swiveljoint coupled to each of the heat exchanging panels 8 and 4 in FIG. 1, afluid return swivel joint coupled to each of the heat exchanging panels6 and 2 in FIG. 1, where the heat exchanging panels 8 and 6 arefluidically coupled in series and the heat exchanging panels 4 and 2 arefluidically coupled in series.

In another exemplary configuration, a single input swivel joint iscoupled to a common cooling door supply line and a pair of output swiveljoints are coupled to the fluid output side of the heat exchangingpanels. Each output swivel joint is coupled to multiple heat exchangingpanels. FIG. 5 illustrates a cooling door assembly 310 configuredaccording to yet another embodiment of the present invention. FIG. 6illustrates an enlarged top portion of the cooling door assembly 310 ofFIG. 5 with a portion of the frame paneling removed. FIG. 7 illustratesan enlarged bottom portion of the cooling door assembly 310 of FIG. 5with a portion of the frame paneling removed. The cooling door assembly310 is configured to be mounted to an electronics enclosure, such as theelectronics enclosure 80 (FIG. 1). The cooling door assembly 310functions similarly as the cooling door assemblies 10, 110 except thecooling door assembly 310 includes a single input swivel joint 328 andtwo output swivel joints 318, 319, as opposed to the single input swiveljoint and single output swivel joint of the cooling door assemblies 10,110. The cooling door assembly 310 also differs from the cooling doorassemblies 10, 110 in that the flex mechanism used for componentalignment is no longer included in the cooling door, but instead isincluded in the frame 312 and/or as part of the mounting mechanism usedto mount the cooling door 314 to the frame 312.

The inlet swivel joint 328 is coupled to an inlet mounting block 316.The mounting block 316 is fluidically coupled to the frame 312 via aframe supply line 326 (FIG. 7) and mechanically coupled to a front frameplate 303 of the frame 312 via a plurality of grommets 317. The grommets317 are made of a flexible and compressible material that provide adegree of float between the mounting block 316 and the front frame plate303. The float provided by the grommets enables movement of the mountingblock relative to the frame so that the mounting block is not rigidlymounted to the frame. In some embodiments, the grommets are made ofrubber.

The outlet swivel joint 330 is coupled to an outlet mounting block 318,and the outlet swivel joint 331 is coupled to an outlet mounting block319. The mounting block 318 is fluidically coupled to the frame 312 viaframe return line 323 (FIG. 6), and the mounting block 319 isfluidically coupled to the frame 312 via a frame return line 329 (FIG.6). Each of the mounting blocks 318, 319 are mechanically coupled to thefront frame plate 303 via a plurality of grommets 315 and 321,respectively.

Each of the swivel joints 328, 330, 331 is configured with a fluid path,which is coupled to a fluid path within the mounting blocks 316, 318,319, respectively. The fluid path through the mounting block 316 and theinlet swivel joint 328 provides a supply fluid path to supply fluid fromthe frame 312 to the cooling door 314. A common cooling door supply line338 (FIG. 7) and 340 (FIGS. 6 and 7) provides fluid from the inletswivel joint 328 to panel supply lines 348, 346, 344, 342 for heatexchanging panels 302, 304, 306, 308, respectively. Fluid is output fromthe heat exchanging panels 306, 308 via panel return lines 352, 350,respectively, to a cooling door return line 359 (FIG. 6). The coolingdoor return line 359 is coupled to the fluid path through the outletswivel joint 331. Similarly, fluid is output from the heat exchangingpanels 302, 304 via panel return lines 356, 354, respectively, to acooling door return line 358 (FIG. 6). The cooling door return line 358is coupled to the fluid path through the outlet swivel joint 330.

The frame return line 329 is coupled to the frame return line 323 via aflexible piping 325. The flexibility of the flexible piping 325 providesindependent movement of the mounting block 318/swivel joint 330 relativeto the mounting block 319/swivel joint 331. If the mounting block318/swivel joint 330 were rigidly coupled to the mounting block319/swivel joint 331, then movement of one would cause movement of theother. However, movement of both the mounting block 318/swivel joint 330and the mounting block 319/swivel joint 331 may not be needed for properalignment. The flexible piping 325 provides this independent movement.

Fluid is output from the frame 312 via frame return interconnects 384,386, which are coupled to external return lines (not shown). The framereturn interconnects 384, 386 are coupled to the frame return line 323.Fluid is input to the frame 312 via frame supply interconnects 380, 382,which are coupled to external supply lines (not shown). The frame supplyinterconnects 380, 382 are coupled to the mounting block 316 via framesupply lines 324 and 326. In some embodiments, flexible piping isincluded in either the frame supply line 324 and/or the frame supplyline 326, such as flexible piping 327. Use of flexible piping in theframe supply lines provides float for properly aligning the mountingblock 316/swivel joint 328.

The movement provided by the grommets and flexible piping enables theswivel joints to float into proper alignment of the cooling doorrelative to the frame. When mounting the cooling door to the frame, thehinge axis and the swivel joint axis must be aligned. The movementprovided by the grommets and/or the flexible piping enable properalignment of the cooling door to the frame.

In some embodiments, the swivel joints 328, 330, 331 are configured asload-bearing elements and therefore also function as hinges. In otherembodiments, hinges independent of the swivel joints are used, in whichcase the swivel joints may or may not be configured as load-bearingelements.

The cooling door assembly 310 can be configured as either a single-phasecooling system or a two-phase cooling system.

Although not shown in FIGS. 1-3, grommets can be used to mount themounting blocks to the frame in the cooling door assemblies 10, 110. Inthe case of a single inlet swivel joint and a single outlet swiveljoint, such as the cooling door assemblies 10, 110, flexible piping inthe frame can also be used, such as part of the frame supply lines 24,124 and/or 26, 126 to provide float for the inlet swivel joint/mountingblock. In some embodiments, the frame interconnection openings (such asinterconnection openings 370 and 374 in FIG. 6, and interconnectionopenings 70, 72, 74, 76 in FIG. 2) are slightly larger than the diameterof the fluid lines that pass through, thereby providing an additionalfloat to be used for alignment of the cooling door to the frame. Ingeneral, a flex mechanism used to properly align the cooling door to theframe includes one, some, or all of any combination of the flexiblepiping in the cooling door and/or the frame, the grommets coupled to themounting blocks, and the float between the interconnection openings andthe fluid lines. The flex mechanism provides float for the swivel jointsto be properly aligned in order to minimize stress.

Embodiments of the cooling door assemblies described above areconfigured with a branching fluid flow path, where fluid is supplied tothe branching fluid flow path by consolidating the fluid input at theexternal supply line interconnects into a common fluid supply for thecooling door. In this manner, the fluid source for these configurationsof the cooling door assembly is conceptually considered as a “singlesource”, although multiple different external supply lines are coupledto the external supply line interconnects. In this context, the fluidflow paths through the frame and cooling door are dependent on thissingle fluid source. For example, a single fluid flow path is providedto the cooling door 14 via the fluid supply lines 24 and 26 in FIG. 1.Similarly, a single flow path is provided to the cooling doors 114 (FIG.3), cooling door 214 (FIG. 4), and cooling door 314 (FIG. 5). Althoughthe cooling doors 14, 114, 214, and 314 each include branching fluidflow paths through the respective cooling doors, and in some casesthrough the frame return lines, these branching fluid paths are alldependent on the common fluid supply provided by the frame supply line.

In other embodiments, the cooling door assembly is configured withseparate and independent fluid paths, where fluid is separately providedto each independent fluid path. In this manner, the fluid source forthis configuration of the cooling door assembly is conceptuallyconsidered as a “multiple source”, where the multiple different externalsupply lines coupled to the external supply line interconnects are notconsolidated into a single source of fluid, but instead are separatelydirected to each of the independent fluid paths, which remainindependent through the frame and the cooling door, and coupledindependently to the external return lines. The heat exchangers withinthe cooling door are configured as groups, the heat exchangers within agiven group are fluidically coupled. A different group of heatexchangers is coupled to each independent fluid path. In the event offailure of one of the independent fluid paths, the other independentfluid path(s) remain operational.

FIG. 8 illustrates a cooling door assembly 410 including multipleindependent fluid paths according to an embodiment of the presentinvention. The cooling door assembly 410 is configured to be mounted toan electronics enclosure, such as the electronics enclosure 80 (FIG. 1).The cooling door assembly 410 functions similarly as the cooling doorassemblies 10, 110, 210, 310 except that the cooling door assembly 410is configured with multiple independent fluid paths. In this exemplaryconfiguration, the cooling door assembly 410 includes a swivel joint 428that includes a single supply fluid path, a swivel joint 430 thatincludes a single return fluid path, and a swivel joint 431 thatincludes two independent fluid paths, one of the independent fluid pathsis a supply fluid path to supply fluid from the frame 412 to the coolingdoor 414, and the other independent fluid path is a return fluid path toreturn fluid from the cooling door 414 to the frame 412. In someembodiments, the two-path swivel joint 431 is a co-axial swivel joint.

The supply fluid path of the swivel joint 428 is coupled to a coolingdoor supply line 440 via a cooling door supply line 438, which can be aflex assembly. The cooling door supply line 440 is coupled to panelsupply lines 442 and 444, which are in turn coupled to heat exchangingpanels 408 and 406, respectively, to receive input fluid. The supplyfluid path of the swivel joint 431 is coupled to a cooling door supplyline 441 via a cooling door supply line 439, which can be a flexassembly. The cooling door supply line 441 is coupled to panel supplylines 446 and 448, which are in turn coupled to heat exchanging panels404 and 402, respectively, to receive input fluid.

The heat exchanging panels 408 and 406 are also coupled to panel returnlines 450 and 452, respectively, to output fluid from the heatexchanging panels. The panel return lines 450 and 452 are coupled to acooling door return line 459, which is coupled to a cooling door returnline 457, which can be a flex assembly. The flex assembly 457 is coupledto the return fluid path of the swivel joint 431. The heat exchangingpanels 404 and 402 are also coupled to panel return lines 454 and 456,respectively, to output fluid from the heat exchanging panels. The panelreturn lines 454 and 456 are coupled to a cooling door return line 458,which is coupled to a cooling door return line 436, which can be a flexassembly. The flex assembly 436 is coupled to the return fluid path ofthe swivel joint 430.

The mounting block 416 includes a supply fluid path, which is coupled tothe supply fluid path of the swivel joint 428 and to a frame supply line426. The frame supply line 426 is coupled to frame supply interconnect480 via frame supply lines 424 and 426. The mounting block 418 includesa return fluid path, which is coupled to the return fluid path of theswivel joint 430 and to a frame return line 422. The frame return line422 is coupled to frame return interconnect 486.

The mounting block 419 includes two independent fluid paths, a supplyfluid path and a return fluid path. The supply fluid path of themounting block 419 is coupled to the supply fluid path of the swiveljoint 431 and to a frame supply line 429. The frame supply line 429 iscoupled to frame supply interconnect 482 via frame supply lines 427 and423. The return fluid path of the mounting block 419 is coupled to thereturn fluid path of the swivel joint 431 and to a frame return line421. The frame return line 421 is coupled to frame return interconnect484.

The cooling door assembly 410 includes two independent fluid paths. Afirst independent fluid path includes the frame supply line interconnect480, the frame supply line 424, the frame supply line 426, the supplyfluid path through the mounting block 416, the supply fluid path throughthe swivel joint 428, the cooling door supply line 438, the cooling doorsupply line 440, the panel supply lines 442 and 444, the heat exchangers406 and 408, the panel return lines 450 and 452, the cooling door returnline 459, the cooling door return line 457, the return fluid paththrough the swivel joint 431, the return fluid path through the mountingblock 419, the frame return line 421, and the frame return lineinterconnect 484. A second independent fluid path includes the framesupply line interconnect 482, the frame supply line 423, the framesupply line 427, the frame supply line 429, the supply fluid paththrough the mounting block 419, the supply fluid path through the swiveljoint 431, the cooling door supply line 439, the cooling door supplyline 441, the panel supply lines 446 and 448, the heat exchangers 402and 404, the panel return lines 454 and 456, the cooling door returnline 458, the cooling door return line 436, the return fluid paththrough the swivel joint 430, the return fluid path through the mountingblock 418, the frame return line 422, and the frame return lineinterconnect 486.

In the exemplary configuration of FIG. 8, the heat exchangers areconfigured into groups of two, with each of the two heat exchangers ineach group positioned adjacent to each other. In alternativeconfigurations, the heat exchangers in each group are not all positionedadjacent to each other, where the supply and return lines arereconfigured accordingly. For example, the heat exchangers 402 and 406can be grouped together as part of a first independent fluid path, andthe heat exchangers 404 and 408 can be grouped together as part of asecond independent fluid path. In other alternative configurations, allgroups of heat exchangers do not have the same number of heatexchangers. In still another alternative embodiment, the heat exchangerscan be grouped into more than two groups, where properly configuredreturn lines, supply lines, swivel joints, mounting blocks,interconnects, etc. are configured to provide the appropriate number ofindependent fluid paths, one independent fluid path for each group ofheat exchangers.

As shown in FIG. 8, the cooling door assembly 410 is configured forsingle-phase cooling since the frame supply interconnects 480, 482 arethe same in diameter as the frame return interconnects 484, 486.Accordingly, each of the supply-side fluid lines are substantially equalin diameter to the return-side fluid lines, as previously described. Inother embodiments, the cooling door assembly 410 is configured fortwo-phase cooling.

The cooling door 414 is mounted to the frame 412 using a plurality ofhinges. In some embodiments, one or more of the swivel joints 430, 431,and 428 are also configured as a load-bearing hinges.

FIG. 9 illustrates a cooling door assembly 510 including multipleindependent fluid paths according to another embodiment of the presentinvention. The cooling door assembly 510 is configured to be mounted toan electronics enclosure, such as the electronics enclosure 80 (FIG. 1).The cooling door assembly 510 functions similarly as the cooling doorassembly 410 except the cooling door assembly 510 includes a singleswivel joint 530 and a single mounting block 518. The swivel joint 530is configured with four independent fluid paths, two independent supplyfluid paths to each supply fluid from the frame 512 to the cooling door514, and two return fluid paths to each return fluid from the coolingdoor 514 to the frame 512. In some embodiments, the four-path swiveljoint 530 is a co-axial swivel joint.

The cooling door assembly 510 includes two independent fluid paths. Afirst independent fluid path includes a frame supply line interconnect580, a first supply fluid path through the mounting block 518, a firstsupply fluid path through the swivel joint 530, a cooling door supplyline 538, which can be a flex assembly, a cooling door supply line 540,panel supply lines 546 and 548, heat exchangers 504 and 502, panelreturn lines 554 and 556, a cooling door return line 558, a cooling doorreturn line 536, which can be a flex assembly, a first return fluid paththrough the swivel joint 530, a first return fluid path through themounting block 518, and a frame return line interconnect 586. A secondindependent fluid path includes a frame supply line interconnect 582, asecond supply fluid path through the mounting block 518, a second supplyfluid path through the swivel joint 530, a cooling door supply line 539,which can be a flex assembly, panel supply lines 542 and 544, heatexchangers 506 and 508, panel return lines 550 and 552, a cooling doorreturn line 537, which can be a flex assembly, a second return fluidpath through the swivel joint 530, a second return fluid path throughthe mounting block 518, and a frame return line interconnect 584.

FIG. 10 illustrates a cooling door assembly 610 including multipleindependent fluid paths according to yet another embodiment of thepresent invention. The cooling door assembly 610 is configured to bemounted to an electronics enclosure, such as the electronics enclosure80 (FIG. 1). The cooling door assembly 610 functions similarly as thecooling door assemblies 410 and 510 except that the fluid supply andreturn between the cooling door and the frame is accomplished using twomultiple-path swivel joints. In this exemplary configuration, thecooling door assembly 610 includes a swivel joint 628 that includes twoindependent fluid paths, each of the independent fluid paths is a supplyfluid path to supply fluid from the frame 612 to the cooling door 614.The cooling door assembly 610 also includes a swivel joint 630 thatincludes two independent fluid paths, each of the independent fluidpaths is a return fluid path to return fluid from the cooling door 614to the frame 612. In some embodiments, one or both of the two-pathswivel joints 628 and 630 are co-axial swivel joints.

The cooling door assembly 610 includes two independent fluid paths. Afirst independent fluid path includes a frame supply line interconnect680, a frame supply line 624, a frame supply line 626, a first supplyfluid path through the mounting block 616, a first supply fluid paththrough the swivel joint 628, a cooling door supply line 637, which canbe a flex assembly, a cooling door supply line 641, panel supply lines646 and 648, heat exchangers 604 and 602, panel return lines 654 and656, a cooling door return line 659, a cooling door return line 638, afirst return fluid path through the swivel joint 630, a first returnfluid path through the mounting block 618, and a frame return lineinterconnect 686. A second independent fluid path includes a framesupply line interconnect 682, a frame supply line 623, a frame supplyline 627, a second supply fluid path through the mounting block 616, asecond supply fluid path through the swivel joint 628, a cooling doorsupply line 639, which can be a flex assembly, a cooling door supplyline 640, panel supply lines 642 and 644, heat exchangers 606 and 608, apanel return lines 650 and 652, a cooling door return line 658, acooling door return line 636, which can be a flex assembly, a secondreturn fluid path through the swivel joint 630, a second return fluidpath through the mounting block 618, and a frame return lineinterconnect 684.

The cooling door assemblies 410, 510, 610 are described above asincluding two independent fluid paths. It is understood that a coolingdoor assembly can be configured with more than two independent fluidpaths. The cooling door assemblies 410, 510, 610 are also described ashaving a one-to-one relationship between the number of external supplylines and the number of independent fluid paths. In alternativeembodiments, two or more external supply lines can be consolidated as a“single source”, which is coupled to an independent fluid path. Ingeneral, each independent fluid path can be coupled to one or moreexternal fluid lines.

The specific configurations of the cooling door assemblies describedabove are for exemplary purposes only. It is understood that otherembodiments, including any combination of the individual components,including the use of flexible piping and flex assemblies, described inthe various configurations are also contemplated.

The cooling door assemblies are described above as including a coolingdoor coupled to a frame, and the frame is mounted to an electronicsenclosure. In this configuration, the cooling door assemblies aremounted to the electronics enclosure without having to add additionalplumbing to the electronics enclosure. Alternatively, the cooling doorsare configured to mount directly to the electronics enclosures. In suchconfigurations, additional plumbing, such as frame supply lines, framereturn lines, and/or mounting blocks, is added to the electronicsenclosure to provide the necessary fluid connections to the externalfluid supply and return lines.

In some embodiments, the cooling door is further configured to providean amount of electro-magnetic interference (EMI) protection, such asadding a screen with opening to allow airflow to the heat exchangers.Additionally, EMI gasketing can be used where the frame attaches to therack and around where the cooling door closes. EMI gasketing functionsto seal the cooling door and restrict the air from leaving the enclosurewithout passing through the heat exchangers in the cooling door.

The present invention has been described in terms of specificembodiments incorporating details to facilitate the understanding of theprinciples of construction and operation of the invention. Suchreference herein to specific embodiments and details thereof is notintended to limit the scope of the claims appended hereto. It will beapparent to those skilled in the art that modifications may be made inthe embodiment chosen for illustration without departing from the spiritand scope of the invention.

What is claimed is:
 1. A cooling door assembly comprising: a. aplurality of external supply line interconnects configured to receive afluid; b. a plurality of external return line interconnects configuredto output the fluid; c. an electronics enclosure; d. a cooling doorincluding a plurality of heat exchangers configured to pass the fluidtherethrough, wherein the cooling door is coupled to the electronicsenclosure; and e. one or more swivel joints coupled to the electronicsenclosure and to the cooling door, wherein each of the one or moreswivel joints includes one or more independent fluid paths, each fluidpath coupled either between one or more of the plurality of the externalsupply line interconnects and one or more of the plurality of heatexchangers, or between one or more of the plurality of heat exchangersand one or more of the plurality of the external return lineinterconnects, thereby forming a plurality of independent fluid pathsthrough the cooling door.
 2. The cooling door assembly of claim 1wherein one or more of the one or more swivel joints comprise an inletswivel joint that includes one or more inlet fluid paths, each inletfluid path coupled between one or more of the plurality of externalsupply line interconnects and one or more of the plurality of heatexchangers.
 3. The cooling door assembly of claim 1 wherein one or moreof the one or more swivel joints comprise an outlet swivel joint thatincludes one or more outlet fluid paths, each outlet fluid path coupledbetween one or more of the plurality of heat exchangers and one or moreof the plurality of external return line interconnects.
 4. The coolingdoor assembly of claim 1 wherein one or more of the one or more swiveljoints includes a plurality of fluid paths, further wherein one or moreof the plurality of fluid paths include an inlet fluid path, each inletfluid path coupled between one of the plurality of external supply lineinterconnects and one or more of the plurality of heat exchangers, andone or more of the plurality of fluid paths include an outlet fluidpath, each outlet fluid path coupled between one or more of theplurality of heat exchangers and one or more of the plurality ofexternal return line interconnects.
 5. The cooling door assembly ofclaim 1 wherein each independent fluid path comprises one or more of theplurality of external supply line interconnects, one or more fluid pathsthrough one or more swivel joints, one or more of the plurality of heatexchangers, and one or more of the plurality of external return lineinterconnects.
 6. The cooling door assembly of claim 1 wherein the oneor more swivel joints are each configured to rotate while maintainingthe one or more independent fluid paths between the plurality ofexternal supply line interconnects, the plurality of heat exchangers,and the plurality of external return line interconnects, therebyenabling the cooling door to rotate relative to the electronicsenclosure while maintaining each independent fluid path through thecooling door.
 7. The cooling door assembly of claim 1 wherein the one ormore of the plurality of heat exchangers in a first independent fluidloop are independent of the one or more of the plurality of heatexchangers in a second independent fluid loop.
 8. The cooling doorassembly of claim 7 wherein a first number of the plurality of heatexchangers in the first independent fluid loop is the same as a secondnumber of the plurality of heat exchangers in the second independentfluid loop.
 9. The cooling door assembly of claim 7 wherein a firstnumber of the plurality of heat exchangers in the first independentfluid loop is different than a second number of the plurality of heatexchangers in the second independent fluid loop.
 10. The cooling doorassembly of claim 1 wherein a first number of the plurality of externalsupply line interconnects in a first independent fluid loop is the sameas a second number of the plurality of external supply lineinterconnects in a second independent fluid loop.
 11. The cooling doorassembly of claim 1 wherein a first number of the plurality of externalsupply line interconnects in a first a independent fluid loop isdifferent than a second number of the plurality of external supply lineinterconnects in a second independent fluid loop.
 12. The cooling doorassembly of claim 1 wherein a first number of the plurality of externalreturn line interconnects in a first independent fluid loop is the sameas a second number of the plurality of external return lineinterconnects in a second independent fluid loop.
 13. The cooling doorassembly of claim 1 wherein a first number of the plurality of externalreturn line interconnects in a first independent fluid loop is differentthan a second number of the plurality of external return lineinterconnects in a second independent fluid loop.
 14. The cooling doorassembly of claim 1 wherein the fluid is a refrigerant.
 15. The coolingdoor assembly of claim 1 wherein the fluid comprises water.
 16. Thecooling door assembly of claim 1 further comprising a plurality of fluidsupply lines coupled between the plurality of external supply lineinterconnects and the one or more swivel joints.
 17. The cooling doorassembly of claim 1 further comprising a plurality of fluid return linescoupled between the one or more swivel joints and the plurality ofexternal return line interconnects.
 18. The cooling door assembly ofclaim 1 wherein the cooling door further comprises a plurality ofcooling door supply lines coupled between the one or more swivel jointsand the plurality of heat exchangers, and a plurality of cooling doorreturn lines coupled between the plurality of heat exchangers and theone or more swivel joints.
 19. The cooling door assembly of claim 18wherein the cooling door further comprises a plurality of heat exchangersupply lines, one heat exchanger supply line for each heat exchanger andeach heat exchanger supply line is coupled between one of the pluralityof cooling door supply lines and the heat exchanger.
 20. The coolingdoor assembly of claim 19 further comprising a flow control regulatorcoupled to each heat exchanger supply line.
 21. The cooling doorassembly of claim 1 further comprising a flow control regulator coupledto at least one of a fluid supply line coupled between one or more ofthe plurality of external supply line interconnects and the one or moreswivel joints, and a cooling door supply line coupled between the one ormore swivel joints and one or more of the plurality of heat exchangers.22. The cooling door assembly of claim 1 further comprises one or moremounting blocks, each one of the one or more mounting blocks is coupledto the electronics enclosure and to one of the one or more swiveljoints.
 23. A cooling door assembly comprising: a. a frame including aplurality of external supply line interconnects configured to receive afluid, and a plurality of external return line interconnects configuredto output the fluid; b. a cooling door including a plurality of heatexchangers configured to pass the fluid therethrough; and c. one or moreswivel joints coupled to the frame and to the cooling door, wherein eachof the one or more swivel joints includes one or more independent fluidpaths, each fluid path coupled either between one or more of theplurality of the external supply line interconnects and one or more ofthe plurality of heat exchangers, or between one or more of theplurality of heat exchangers and one or more of the plurality of theexternal return line interconnects, thereby forming a plurality ofindependent fluid paths through the frame and the cooling door.
 24. Thecooling door assembly of claim 23 wherein one or more of the one or moreswivel joints comprise an inlet swivel joint that includes one or moreinlet fluid paths, each inlet fluid path coupled between one or more ofthe plurality of external supply line interconnects and one or more ofthe plurality of heat exchangers.
 25. The cooling door assembly of claim23 wherein one or more of the one or more swivel joints comprise anoutlet swivel joint that includes one or more outlet fluid paths, eachoutlet fluid path coupled between one or more of the plurality of heatexchangers and one or more of the plurality of external return lineinterconnects.
 26. The cooling door assembly of claim 23 wherein one ormore of the one or more swivel joints includes a plurality of fluidpaths, further wherein one or more of the plurality of fluid pathsinclude an inlet fluid path, each inlet fluid path coupled between oneof the plurality of external supply line interconnects and one or moreof the plurality of heat exchangers, and one or more of the plurality offluid paths include an outlet fluid path, each outlet fluid path coupledbetween one or more of the plurality of heat exchangers and one or moreof the plurality of external return line interconnects.
 27. The coolingdoor assembly of claim 23 wherein each independent fluid path comprisesone or more of the plurality of external supply line interconnects, oneor more fluid paths through one or more swivel joints, one or more ofthe plurality of heat exchangers, and one or more of the plurality ofexternal return line interconnects.
 28. The cooling door assembly ofclaim 23 wherein the one or more swivel joints are each configured torotate while maintaining the one or more independent fluid paths betweenthe plurality of external supply line interconnects, the plurality ofheat exchangers, and the plurality of external return lineinterconnects, thereby enabling the cooling door to rotate relative tothe frame while maintaining each independent fluid path through theframe and the cooling door.
 29. The cooling door assembly of claim 23wherein the one or more of the plurality of heat exchangers in a firstindependent fluid loop are independent of the one or more of theplurality of heat exchangers in a second independent fluid loop.
 30. Thecooling door assembly of claim 29 wherein a first number of theplurality of heat exchangers in the first independent fluid loop is thesame as a second number of the plurality of heat exchangers in thesecond independent fluid loop.
 31. The cooling door assembly of claim 29wherein a first number of the plurality of heat exchangers in the firstindependent fluid loop is different than a second number of theplurality of heat exchangers in the second independent fluid loop. 32.The cooling door assembly of claim 23 wherein a first number of theplurality of external supply line interconnects in a first independentfluid loop is the same as a second number of the plurality of externalsupply line interconnects in a second independent fluid loop.
 33. Thecooling door assembly of claim 23 wherein a first number of theplurality of external supply line interconnects in a first independentfluid loop is different than a second number of the plurality ofexternal supply line interconnects in a second independent fluid loop.34. The cooling door assembly of claim 23 wherein a first number of theplurality of external return line interconnects in a first independentfluid loop is the same as a second number of the plurality of externalreturn line interconnects in a second independent fluid loop.
 35. Thecooling door assembly of claim 23 wherein a first number of theplurality of external return line interconnects in a first a independentfluid loop is different than a second number of the plurality ofexternal return line interconnects in a second independent fluid loop.36. The cooling door assembly of claim 23 wherein the door frame isconfigured to be coupled to an electronics enclosure.
 37. The coolingdoor assembly of claim 23 wherein the fluid is a refrigerant.
 38. Thecooling door assembly of claim 23 wherein the fluid comprises water. 39.The cooling door assembly of claim 23 wherein the frame furthercomprises a plurality of frame supply lines coupled between theplurality of external supply line interconnects and the one or moreswivel joints.
 40. The cooling door assembly of claim 23 wherein theframe further comprises a plurality of frame return lines coupledbetween the one or more swivel joints and the plurality of externalreturn line interconnects.
 41. The cooling door assembly of claim 23wherein the cooling door further comprises a plurality of cooling doorsupply lines coupled between the one or more swivel joints and theplurality of heat exchangers, and a plurality of cooling door returnlines coupled between the plurality of heat exchangers and the one ormore swivel joints.
 42. The cooling door assembly of claim 41 whereinthe cooling door further comprises a plurality of heat exchanger supplylines, one heat exchanger supply line for each heat exchanger and eachheat exchanger supply line is coupled between one of the plurality ofcooling door supply lines and the heat exchanger.
 43. The cooling doorassembly of claim 42 further comprising a flow control regulator coupledto each heat exchanger supply line.
 44. The cooling door assembly ofclaim 23 further comprising a flow control regulator coupled to at leastone of a frame supply line coupled between one or more of the pluralityof external supply line interconnects and the one or more swivel joints,and a cooling door supply line coupled between the one or more swiveljoints and one or more of the plurality of heat exchangers.
 45. Thecooling door assembly of claim 23 wherein the frame further comprisesone or more mounting blocks, each one of the one or more mounting blocksis coupled to one of the one or more swivel joints.